We need to recompute transformGraph, I try to do this intelligently
depending on params change only.

Also, I added preservation of louvain colouring.

Also, fixed graph comparison function.

This should be both fast and more exact now (previously it only
compared node/edge list sizes, now it compares their appropriate
hashes).

Removes duplications in Reactix.purs.

This reverts commit a6ec0726.

This is because useSession wasn't working there.

'useSession' in context

However, there is an issue that the snapshotted graph doesn't render
for some reason. (sigma.graph.nodes() is empty, why?)